Biomaterial Database

Measurement of free, one-chain tissue-type plasminogen activator in human plasma with an enzyme-linked immunosorbent assay based on an active site-specific murine monoclonal antibody. 1987

P Holvoet, and J Boes, and D Collen

An enzyme-linked immunosorbent assay for free tissue-type plasminogen activator (t-PA) in human blood was developed based on a murine monoclonal antibody directed against the active site of t-PA. The lower limit of sensitivity of the assay applied to plasma is 2 ng/mL for one-chain t-PA but only 100 ng/mL for two-chain t-PA. Free t-PA in plasma taken at rest was found in 6 of 21 healthy subjects (4.5 +/- 0.8 ng/mL, mean +/- SD) and increased to 14 +/- 7.0 ng/mL after venous occlusion in 18 of these individuals. A linear correlation between total t-PA and free t-PA was observed with r = 0.92 (n = 18) and a slope of 1.08, indicating that t-PA released from the vessel wall circulates in the blood as the one-chain form. In 16 of 18 patients with deep vein thrombosis, the increase of total t-PA antigen after venous occlusion was comparable to that observed in controls, but the free t-PA was significantly lower or undetectable. The present assay for free t-PA may be useful for the investigation of the release and inhibition of t-PA under physiological, pharmacological, or pathological conditions in humans.

UI	MeSH Term	Description	Entries
D010959	Tissue Plasminogen Activator	A proteolytic enzyme in the serine protease family found in many tissues which converts PLASMINOGEN to FIBRINOLYSIN. It has fibrin-binding activity and is immunologically different from UROKINASE-TYPE PLASMINOGEN ACTIVATOR. The primary sequence, composed of 527 amino acids, is identical in both the naturally occurring and synthetic proteases.	Alteplase,Plasminogen Activator, Tissue-Type,T-Plasminogen Activator,Tissue-Type Plasminogen Activator,Actilyse,Activase,Lysatec rt-PA,TTPA,Tisokinase,Tissue Activator D-44,Lysatec rt PA,Lysatec rtPA,Plasminogen Activator, Tissue,Plasminogen Activator, Tissue Type,T Plasminogen Activator,Tissue Activator D 44,Tissue Type Plasminogen Activator
D004797	Enzyme-Linked Immunosorbent Assay	An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.	ELISA,Assay, Enzyme-Linked Immunosorbent,Assays, Enzyme-Linked Immunosorbent,Enzyme Linked Immunosorbent Assay,Enzyme-Linked Immunosorbent Assays,Immunosorbent Assay, Enzyme-Linked,Immunosorbent Assays, Enzyme-Linked
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000911	Antibodies, Monoclonal	Antibodies produced by a single clone of cells.	Monoclonal Antibodies,Monoclonal Antibody,Antibody, Monoclonal
D000918	Antibody Specificity	The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.	Antibody Specificities,Specificities, Antibody,Specificity, Antibody
D000939	Epitopes	Sites on an antigen that interact with specific antibodies.	Antigenic Determinant,Antigenic Determinants,Antigenic Specificity,Epitope,Determinant, Antigenic,Determinants, Antigenic,Specificity, Antigenic
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D013927	Thrombosis	Formation and development of a thrombus or blood clot in BLOOD VESSELS.	Atherothrombosis,Thrombus,Blood Clot,Blood Clots,Thromboses